I'm adding the CB module to my HK unit.

Looking through the parts diagrams, it looks like bikes up through '08 used a load coil and tunable antenna, and '09+ use a pre-tuned antenna and omit the separate coil.

The parts I would need price out to be nearly the same going either way. Does anyone have an opinion on which antenna system works better? I have a shelf in my TP that would cover the load coil, so space isn't a consideration.

 

I would go with the tunable antenna. That way you can actually resonate the antenna to maximize your transmitted power into the air. I'd do this rather than have it turn into heat through some inbuilt capacitive/reactance gimmick that a 'pretuned' antenna will come with. Newer is not necessarily better.